Java 代码

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();
        int a = sc.nextInt();
        int b = sc.nextInt();


        HashMap<Integer, Pair> map = new HashMap<>();

        while (a-->0) {
            int index = sc.nextInt();
            int value = sc.nextInt();
            map.put(index, new Pair(value,0));
        }
        while (b-->0) {
            int index = sc.nextInt();
            int value = sc.nextInt();
            if (map.containsKey(index)) {
                Pair pair = map.get(index);
                pair.v2 = value;
            }

        }


        Set<Map.Entry<Integer, Pair>> entries = map.entrySet();
        long res = 0;
        for (Map.Entry<Integer, Pair> entry : entries) {
            Pair pair = entry.getValue();
            res += (long) pair.v1 * (long) pair.v2;
        }

        System.out.println(res);


    }

    static class Pair {
        int v1;
        int v2;

        Pair (int v1, int v2) {
            this.v1 = v1;
            this.v2 = v2;
        }

    }

}